1. Field of the Invention
The present invention relates generally to the field of converting heat energy directly to electrical energy, and more particularly to apparatus having a thermionic source of electrons, which electrons subsequently produce currents in an induction coil for energizing externally connected loads.
2. Description of the Prior Art
Heretofore, there have been known thermionic converters such as shown in U.S. Pat. Nos. 3,519,854 and 3,328,611 (both to the inventor of the present invention) which disclose apparatus and methods for the direct conversion of thermal energy to electrical energy. In U.S. Pat. No. 3,519,854 there is described a converter using a Hall effect techniques as the output current collection means. The U.S. Pat. No. 3,519,854 teaching is of interest in that it uses as its source of electrons a stream boiled off of an emissive cathode surface and accelerated towards an anode positioned beyond the Hall effect transducer. In U.S. Pat. No. 3,328,611, a spherically configured thermionic converter is disclosed wherein a spherical, emissive cathode is supplied with heat (from several alternate sources including a self-contained fuel combustion section) thereby emitting electrons to a concentrically positioned, spherical anode under the influence of a control member having a high positive potential thereon.
While the above two illustrative examples of prior art thermionic converters teach apparatus for accomplishing the desired direct conversions, and while a good deal of additional inventive effort has been directed to the practical and theoretical problems associated with such conversion means, it is clear that there continues to be a need for improved devices and methods for direct thermal/electric converters.